Curtain airbag device and method of manufacturing the same

ABSTRACT

To provide a structure of an airbag capable of maintaining an attaching stability of the airbag for a long period and a method of manufacturing the airbag. Further, an object is to provide a structure of a curtain airbag device capable of easily coupling an airbag body with brackets without requiring special equipment when they are coupled with each other and a method of manufacturing the curtain airbag device. 
     The curtain airbag device of the invention has a bag body accommodated to a window upper edge of a vehicle for expanding and inflating toward inside of the vehicle in a compressed state when it is operated, a plurality of strip-shaped coupling members coupled with the bag body, and a plurality of brackets coupled with the bag body for fixing the bag body to the vehicle. Each bracket has a coupling hole through which each strip-shaped coupling member is inserted and a fixing hole into which a predetermined tightening member is inserted. The bag body is coupled with the brackets by the strip-shaped coupling members as well as the bag body is fixed to the vehicle through the brackets by the tightening members.

TECHNICAL FIELD

The present invention relates to a curtain airbag device for protecting passengers by inflating an airbag (bag body) inside of windows in a curtain state when a vehicle emergency (a roll-over, a lateral collision, an overturn, and the like) occurs. More particularly, the invention relates to a structure of portions of a curtain airbag attached to a vehicle.

BACKGROUND ART

In general, an inner panel (body panel) covered by a headlining (roof) is disposed above side windows of a passenger compartment. A bag body of a curtain airbag is accommodated in a folded state in a space formed by the headlining and the inner panel (Patent Documents 1 and 2). When the curtain airbag device is operated, the bag body is expanded by a gas supplied from an inflator and inflated into a compartment by pushing down and expanding the lower edge of the headlining.

-   Patent Document 1: Japanese Patent Application Laid-Open No.     2001-219807 -   Patent Document 2: Japanese Patent Application Laid-Open No.     2002-187518

Conventionally, when a curtain airbag is attached to a vehicle, a cushion (airbag body) is clamped by metal parts (brackets), and the brackets are coupled with and fixed to the cushion by partly deforming the brackets. The curtain airbag has such a structure that bolt holes are formed to the brackets, and bolts are inserted through the brackets and the cushion passing through the bolt holes and fixed to the vehicle. However, in the structure described above, since the cushion exists between the brackets, there is a possibility that an initial torque at the time when the brackets are fixed by the bolts is lowered as a time passes. Further, when the brackets are coupled with the cushion, since the brackets are attached to the cushion by being deformed, dedicated equipment is required in a manufacturing process of the airbag.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

A first object of the present invention, which was made in view of the above circumstances, is to provide an airbag device, which can maintain an airbag attaching stability (a tightening torque) for a long period and a method of manufacturing the airbag device.

Further, a second object is to provide an airbag device which can easily couple an airbag body (cushion) with brackets without requiring special equipment when they are coupled with each other and a method of manufacturing the airbag device.

Means for Solving the Problems

In order to solve the above problems, a curtain airbag device according to a first aspect of the present invention has a bag body accommodated to a window upper edge of a vehicle for expanding and inflating toward inside of the vehicle in a compressed state when it is operated, a plurality of strip-shaped coupling members coupled with the bag body, and a plurality of brackets coupled with the bag body for fixing the bag body to the vehicle. Each of the plurality of brackets has a coupling hole through which each of the strip-shaped coupling members is inserted and a fixing hole into which a predetermined tightening member is inserted. The bag body is coupled with the brackets by the strip-shaped coupling members as well as the bag body is fixed to the vehicle through the brackets by the tightening members.

A method of manufacturing a curtain airbag device according to a second aspect of the invention has a step of coupling the airbag body with the brackets by inserting the one end of the strip-shaped coupling members through the coupling holes of the brackets and then coupling both the ends with the bag body, and a step of folding and compressing the airbag body including the brackets.

Effects of the Invention

According to the curtain airbag device of the present invention with the above structure, since the brackets are directly tightened and fixed to the vehicle without interposing the bag body (cushion) therebetween, a tightening torque can be suppressed from being reduced as a time passes.

Since the bag body is coupled with the brackets by inserting the strip-shaped coupling members through the coupling holes formed to the brackets and sewing, for example, both the ends of strip-shaped coupling members to the bag body, a coupling job can be easily performed without using special equipment.

Further, in the invention, since the brackets can be caused to come into contact with the strip-shaped coupling members over the entire surfaces of the strip-shaped coupling members, there is a merit in that the coupling strength of the brackets with the bag body and further the coupling strength of the vehicle with the bag body can be improved. More specifically, when the bag body is inflated at the time the airbag device is operated and a force for pulling the brackets downward acts on the brackets, the force can be supported by the entire width of the strip-shaped coupling members. In contrast, in a conventional art, even if a strip-shaped coupling member is clamped between two brackets, a large force acts in a very small range as in a case that the force is substantially supported in portions where bolts are in contact with coupling members (tabs). Accordingly, there is a case that the portion, where the bracket is coupled with the tab, must be reinforced to obtain the strength of the portion.

Note that it is preferable to design the brackets (coupling holes) and the strip-shaped coupling members so that the strip-shaped coupling members optionally move with respect to the brackets. When the strip-shaped coupling members freely (smoothly) move with respect to the brackets, the brackets can be kept in a free attitude without being restricted by the long and relatively heavy bag body. As a result, an attachment job to the vehicle can be easily performed using a tightening tool such as bolts and the like.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a passenger compartment having a curtain airbag device according to an example of the present invention.

FIG. 2A and FIG. 2B are explanatory views showing a structure of a main portion of the curtain airbag device according to a first example of the invention, wherein FIG. 2A shows a state that a bracket is coupled with a bag body, and FIG. 2B shows a state of a tab before the bracket is attached.

FIG. 3A and FIG. 3B are explanatory views showing a structure of a main portion of a curtain airbag device according to a second example of the invention, wherein FIG. 3A shows a state that a bracket is coupled with a bag body, and FIG. 3B shows a state before the bracket is attached. FIG. 3 are longitudinal sectional views showing the structure of the airbag body used for instruction.

BEST MODE FOR CARRYING OUT THE INVENTION

An example of the present invention will be explained below with reference to the drawings.

FIG. 1 is a sectional view of a passenger compartment having a curtain airbag device according to the example of the present invention. As shown in FIG. 1, for example, in a passenger car type vehicle, an inner panel covered by a headlining is disposed above side windows of the passenger compartment. The curtain airbag device is fixed to the inner panel by bolts using brackets 100. In FIG. 1, reference numeral 102 denotes fixing holes (bolt holes) for the bolts formed to the brackets 100.

The curtain airbag device has a bag body 12 and a gas supply unit (inflator) 14. The bag body 12 is accommodated in a state that it is covered by the headlining disposed to a window upper edge of the vehicle and protects passengers in the vehicle by being expanded and inflated downward from a gap between the headlining and the inner panel when it is operated, and the inflator 14 supplies an expansion gas to the bag body 12.

The bag body 12 is formed in a bag-shaped body by sewing, bonding, or welding two overlapping sheets or has a bag portion formed by weaving a single sheet. The bag body 12 has a plurality of chambers which expand when the bag body 12 is operated and a duct portion which extends in a longitudinal direction on the upper side of the chambers and distributes the gas to the respective chambers. A method of folding the bag body 12 is not particularly limited and various methods such as a so-called “accordion folding” method, a “rolling” method, and the like can be employed.

When an emergency such as a roll-over, a lateral collision, an overturn, and the like occurs while a vehicle is moving, a sensor disposed to the vehicle detects abnormal vibrations and sends an ignition signal to the not shown inflator (gas generation unit) 14 based on the signal. The inflator 14 has a propellant which is disposed therein and drives the inflator 14 in response to the ignition signal from the sensor. The expansion gas is filled in the bag body 12 by operating the inflator 14, and the bag body 12 is inflated so that the headlining is pressed down and expanded (forcibly torn and blown off). The side windows are covered by the inflated bag body 12 so that the passengers in the vehicle are protected.

FIG. 2A and FIG. 2B are explanatory views showing a structure of a main portion of a curtain airbag device according to a first example of the invention, wherein the FIG. 2A shows a state that a bracket 100 is coupled with a bag body 12, and the FIG. 2B shows a state of a tab 106 before the bracket 100 is attached thereto. The curtain airbag device according to the example has the bag body 12, a plurality of the tabs 106, and a plurality of the brackets 100. The bag body 12 is accommodated to a window upper edge of a vehicle in a compressed state and expanded and inflated toward inside of the vehicle when it is operated, the plurality of tabs 106 are coupled with the bag body 12, and the plurality of brackets 100 fix the bag body 12 to the vehicle.

The plurality of brackets 100 have slit-shaped coupling holes 104, through which the tabs 106 are inserted, circular fixing holes 102 through which bolts are inserted. The bag body 12 is coupled with the brackets 100 by the tabs 106. The bag body 12 is fixed to the vehicle by the bolts (not shown) through the brackets 100.

As shown in FIG. 2B, the strip-shaped tab 106 is formed of the same material as that of the bag body 12 integrally therewith. An end portion 106 a of the tab 106 is annularly formed passing through the coupling hole 104 of the bracket 100 and is sewed to a portion which is coupled with the bag body 12 or to the other end of the tab 106 itself.

The bracket 100 is molded of a metal sheet having a strength sufficient to support the bag body 12 that is expanded and inflated. The fixing hole 102 has an inside diameter which is necessary for the bolt to pass therethrough. The coupling hole 104, through which the tab 106 passes, is formed in a laterally long slit-shape and has a width and a height to allow the tab 106 to easily move therein.

When the curtain airbag device arranged as described above is manufactured (assembled), after the end portions 106 a of the tabs 106 are inserted through the coupling holes 104 of the brackets 100, the end portions 106 a are sewed to the bag body 12 or to the end portions (roots) of the tabs 106. As a result, the airbag body 12 is coupled with the brackets 100. In this state, the airbag body 12 having the brackets 100 is folded and compressed.

When the curtain airbag device according to the first example is assembled to the vehicle, the airbag device, which is folded to a thick rope-shape, is carried to the vicinity of the window upper edge, the bolts (not shown) are inserted into the fixing holes 102 of the brackets 100, and the airbag device is fixed to the vehicle by tightening the bolts.

In the first example, since the brackets 100 are directly tightened and fixed to the vehicle without interposing the bag body (cushion) 12 therebetween, a tightening torque can be suppressed from being reduced as a time passes.

Since the bag body 12 is coupled with the brackets 100 by inserting the tabs 106 through the coupling holes 104 formed to the brackets 100 and sewing the end portions of the tabs 106, a coupling job can be easily performed without using special equipment.

Further, since the coupling holes 104 of the bracket 100 and the tabs 106 are designed so that the tabs 106 freely move to the brackets 100, the brackets 100 can be kept in a free attitude without being restricted by the long and relatively heavy bag body 12. As a result, an attachment job to the vehicle can be easily performed using a tightening tool of a bolt and the like.

FIG. 3A and FIG. 3B are explanatory views showing a structure of a main portion of a curtain airbag device according to a second example of the present invention, wherein FIG. 3A shows a state that a bracket 100 is coupled with a bag body 212, and FIG. 3B shows a state before the bracket 100 is attached thereto. The curtain airbag device according to the second example is different from the airbag device according to the first example described above in that strip-shaped coupling members 206 are composed of members different from the bag body 212. Since the other main arrangements of the second example are similar to those of the first example, an overlapping explanation is omitted.

As shown in FIG. 3B, each strip-shaped coupling member 206 is composed of the member different from the bag body 212 and has an end portion 206 a inserted through a coupling hole 104 of each bracket 100. With this arrangement, the strip-shaped coupling member 206 is formed in annular shape and sewed to a portion with which the bag body 212 is coupled or to the other end of the strip-shaped coupling member 206 itself. A structure of the bracket 100 is similar to that of the first example described above.

When the curtain airbag device is manufactured (assembled), one end of the strip-shaped coupling members 206 are previously sewed to the upper edge portion of the bag body 212. Next, after the end portions 206 a of the strip-shaped coupling members 206 are inserted through the coupling holes 104 of the brackets 100, the end portions 206 a are sewed to the bag body 212 or to the end portions (roots) of the strip-shaped coupling members 206. With this operation, the airbag body 212 is coupled with the brackets 100. In this state, the airbag body 12 having the brackets 100 is folded and compressed. Note that it is also possible to sew and fix both the ends of the strip-shaped coupling members 206 to the bag body 212 at the same time after the strip-shaped coupling members 206 are inserted through the coupling holes 104 of the brackets 100.

A method of assembling the curtain airbag device according to the second example to a vehicle is also similar to that of the first example described above.

Since the strip-shaped coupling member 206 is composed of the different members in the second example, there is an advantage in that a degree of freedom of a coupling job for coupling the brackets 100 to the bag body 212 is increased in addition to the advantage of the first example described above. More specifically, for example, it is possible to perform a sewing job at the same time to a plurality of units, each of which has the strip-shaped coupling member 206 caused to previously pass through the coupling hole 104 of the bracket 100 and which are disposed along the edge portion of the bag body 212.

Although the examples of the present invention have been explained above, the present invention is not limited to the examples and can be variously modified in design and the like within the scope which does not depart from the technical idea disclosed in the claims. It is needless to say, for example, that the curtain airbag device according to the invention can be applied not only to a passenger car type vehicle but also to various types of vehicles such as one-box type vehicle and the like. Further, although the material of the brackets 10 is the metal in the examples, other material (resin and the like) having a sufficient mechanical strength may be used.

DESCRIPTION OF REFERENCE NUMERALS

-   12: bag body -   14: inflator -   100: bracket -   102: fixing hole -   104: coupling hole -   106: tab -   108: sewed portion -   206: strip-shaped portion coupling member -   208: sewed portion -   212: bag body 

1. A curtain airbag device, characterized by comprising: a bag body accommodated to a window upper edge of a vehicle in a compressed state for expanding and inflating toward inside of the vehicle when it is operated; a plurality of strip-shaped coupling members coupled with the bag body; and a plurality of brackets coupled with the bag body for fixing the bag body to the vehicle, wherein, each of the plurality of brackets has a coupling hole through which each of the strip-shaped coupling members is inserted and a fixing hole into which each of predetermined tightening members is inserted, the bag body is coupled with the brackets by the strip-shaped coupling members, and the bag body is fixed to the vehicle by the tightening members through the brackets.
 2. The curtain airbag device according to claim 1, characterized in that the strip-shaped coupling members have such a structure that ends are fixed to the bag body.
 3. The curtain airbag device according to claim 2, characterized in that the ends of the strip-shaped coupling members are coupled with the bag body by sewing.
 4. The curtain airbag device according to claim 1, 2, or 3, characterized in that the strip-shaped coupling members are tabs formed of the same material as that of the bag body integrally therewith.
 5. The curtain airbag device according to claim 1, 2, or 3, characterized in that the strip-shaped coupling members are arranged as members different from the bag body.
 6. A method of manufacturing the airbag device according to claim 1, characterized by comprising: a step of coupling the airbag body with the brackets by inserting the one end of the strip-shaped coupling members through the coupling holes of the brackets and then coupling both the ends with the bag body; and a step of folding and compressing the airbag body including the brackets.
 7. The method of manufacturing the curtain airbag device according to claim 6, characterized in that the ends of the strip-shaped coupling members are coupled with the bag body by sewing.
 8. The method of manufacturing the curtain airbag device according to claim 6 or 7, characterized in that the strip-shaped coupling members are tabs formed of the same material as that of the bag body integrally therewith.
 9. The method of manufacturing the curtain airbag device according to claim 6 or 7, characterized in that the strip-shaped coupling members are arranged as members different from the bag body.
 10. A curtain airbag device, characterized by comprising: a bag body accommodated to a window upper edge of a vehicle in a compressed state for expanding and inflating toward inside of the vehicle when it is operated; a plurality of strip-shaped coupling members coupled with the bag body; and a plurality of brackets coupled with the bag body for fixing the bag body to the vehicle, wherein each of the plurality of brackets includes: a coupling hole through which each of the strip-shaped coupling members is inserted; and a fixing hole through which a tightening member for fixing the bag body to the vehicle is inserted through the brackets, and the bag body is coupled with the brackets by the strip-shaped coupling members.
 11. The curtain airbag device according to claim 10, characterized in that the strip-shaped coupling members have such a structure that ends are fixed to the bag body.
 12. The curtain airbag device according to claim 11, characterized in that the ends of the strip-shaped coupling members are coupled with the bag body by sewing.
 13. The curtain airbag device according to claim 10, 11, or 12, characterized in that the strip-shaped coupling members are tabs formed of the same material as that of the bag body integrally therewith.
 14. The curtain airbag device according to claim 10, 11, or 12, characterized in that the strip-shaped coupling members are arranged as members different from the bag body.
 15. A method of manufacturing the airbag device according to claim 10, characterized by comprising: a step of coupling the airbag body with the brackets by inserting the one end of the strip-shaped coupling members through the coupling holes of the brackets and then coupling both the ends with the bag body; and a step of folding and compressing the airbag body including the brackets.
 16. The method of manufacturing the curtain airbag device according to claim 15, characterized in that the ends of the strip-shaped coupling members are coupled with the bag body by sewing.
 17. The method of manufacturing the curtain airbag device according to claim 15 or 16, characterized in that the strip-shaped coupling members are tabs formed of the same material as that of the bag body integrally therewith.
 18. The method of manufacturing the curtain airbag device according to claim 15 or 16, characterized in that the strip-shaped coupling members are arranged as members different from the bag body. 